Middle Mediastinum Flashcards
mediastinum
area where the heart sits between the two pleural cavities
Where is the mediastinum located?
between the lungs, sternum, and vertebral column
What does the mediastinum contain?
heart and its great vessels, trachea, esophagus, thymus, lymph vessels/nodes, nerves, vessels and connective tissue
Superior Mediastinum
superior to a line from the sternal angle anteriorly to the T4/T5 intervertebral disc posteriorly
Anterior mediastinum
between body of the sternum and pericardial sac, superior to the diaphragm and inferior to the superior mediastinum
Posterior mediastinum
between the pericardial sac anteriorly and T5-T12 vertebrae posteriorly
MIddle Mediastinum
Contains pericardial sac, heart, roots of the great vessels, phrenic nerve, pericardiophrenic vessels, arch of azygos, and main bronchi
Pericardial sac
Surrounds heart
bound to the central tendon of the diaphragm
fused with the tunica adventitia of the great vessels
anchors the heart within the mediastinum
prevents overstitching of the heart
fibrous pericardium
outer surface of the pericardial sac. it is fibrous and tough
serous pericardium
inner surface of the pericardial sac. smooth and shiny.
parietal layer
covers the inner surface of the fibrous pericardium
visceral layer (epicardium)
adheres to the heart
pericardial cavity
between the parietal and visceral layers of the serous pericardium. A potential space between the opposing layers of the serous pericardium. contains a thin film of fluid that enables the heart to move and beat in a frictionless environment
pericardiacophrenic vessels
Main blood supply to and form the fibrous pericardium and parietal layer of the serous pericardium
Phrenic nerves
C3, C4, C5 (keeps the diaphragm alive). main source of sensory fibers for the pain sensations to the fibrous pericardium and parietal layer of serous pericardium
Coronary arteries
supply blood to the visceral layers of the serous pericardium.
Cardiac Veins
drain blood from the visceral layer of the serous pericardium
Vagus nerves
provide sensory fibers to the visceral layer of the serous pericardium
Apex of the heart
bottom of the heart, mostly left ventricle. inferolateral end of the heart, formed by the tip of the left ventricle
How much of the heart is on the left side of the body?
2/3
base of the heart
superior end of the heart, where the great vessels enter exit the chambers, formed mainly by the left atrium
what are the 3 layers of the heart?
epicardium
myocardium
endocardium
epicardium
visceral layer of the serous pericardium. thin, transparent and adheres to the heart
myocardium
the muscular wall of the heart, it is the cardiac muscle tissue responsible for the heart’s pumping action.
Endocardium
provides the smooth lining of the inside of the heart chambers and covers the valves of the heart
interarterial septum
separates the 2 atria
interventricular septum
separates the 2 ventricles
Auricles
Power boosters, made of pectin muscle. Superficial superior to the left and right atria
Anterior interventricular sulcus
down the center of the heart on the outside between the two ventricles
Coronary sulcus
atrioventricular sulcus
What separates the heart into top and bottom halves?
the AV valves
What is the right AV valve?
tricuspid
What is the left AV valve?
bicupsid/mitral valve
Heart murmur
abnormal heart sound, blowing or vibration noise caused by turbulent flow of blood. Usually indicates a valve disorder (normally mitral), which may or may not be asymptomatic
pulmonary circuit
right side of the heart. pumps deoxygenated blood into the pulmonary circulation to the lungs
systemic circulation
left side. pumps oxygenated blood into the systemic circulation to all tissues of the body.
Right atrium receives blood from
superior vena cava, inferior vena cava and coronary sinus
Crista terminalis
smooth line on wall of RA.
What kind of muscle is on the inner wall of RA?
pectinate muscle
fossa ovalis
after birth, it becomes a “thumbprint” shaped indention in the wall of AR on the inter arterial side
probe patent foramen
if the foramen oval (fossa ovalis before birth) does not close after birth, forming the fossa Novalis, this forms. It is a hole in the heart. Large hole can over burden the pulmonary circuit
Papillary muscles
anterior, posterior, septal. hold the chordae tendonae
Where does the anterior papillary muscle attach?
moderator band
chordae tendonae
string like projections that help keep the valves closed to prevent back flow of blood in the atria
trabeculae carneae
muscle on interior of ventricle
pulmonary semi lunar valves
goes from right ventricle to the pulmonary trunk
conus arteriosus
the area just before he pulmonary semilunar valves in the RV
Moderator band
connects the anterior papillary muscles. also called the septomarginal trabeculae
Flow of blood in pulmonary circulation
Superior/Inferior vena cava and Coronary sinus—RA—tricuspid—RV—pulmonary semilunar valve—pulmonary trunk—left/right pulmonary arteries—lungs—
